Car raising temperature

[patrickcortes10]

Guys, I have a 2008 aspirated Legacy 3.0. My car is getting hot easily. Any climb greater than 2 miles, going up to 60 mph, the car reaches 212°F, and then I have to take my foot off, it quickly returns to 203°F, if I accelerate hard it reaches 215°F which is when the needle passes the middle and begins to boil. At high speeds for a few minutes the car also reaches these temperatures. Considerations, I live in a tropical country and in a very hot state. Outdoor temperature 90 - 100°F. Maintenance already carried out: I changed all the fluid in the cooling system and cleaned the system, I changed all the radiator hoses, the car does not leak any fluid, I changed the two thermostatic valves. In heavy traffic, my car doesn't heat up, only when driving at high speed or climbing mountains. I would like to know if anyone has experienced something similar and can help me, I don't know if there is an update for the system.

[KZJonny]

You’ve already done the peripheral work, how about the radiator itself.

Often the welds between the cooling fins and coolant passages cab begin to degrade and separate without appearing to be bad.

Might be worth a very close inspection to ensure they are still good. If the rad is original 2008, there is a good chance it is at the end of it’s life and just isn’t doing a good job of rejecting heat anymore.

[patrickcortes10]

1 hour ago, KZJonny said:

Você já fez o trabalho periférico, que tal o próprio radiador.

Freqüentemente, as soldas entre as aletas de resfriamento e as passagens de refrigerante da cabine começam a se degradar e a se separar sem parecerem ruins.

Pode valer a pena uma  inspeção muito  minuciosa para garantir que ainda estão bons. Se o rad for original de 2008, há uma boa chance de que ele esteja no fim de sua vida útil e simplesmente não esteja mais fazendo um bom trabalho de rejeição de calor.

Thanks for your tip. I will request an inspection. However, the last owner of the car stated that he changed the radiator.

[KZJonny]

1 minute ago, patrickcortes10 said:

Thanks for your tip. I will request an inspection. However, the last owner of the car stated that he changed the radiator.

Got you. It wasn't mentioned in the original post, so I it seemed like the most obvious solution. It's probably something you can do yourself, rather than having it inspected by someone else, but IF the rad it pretty new then it likely isn't a problem.

2 hours ago, patrickcortes10 said:

I changed all the fluid in the cooling system and cleaned the system

Was this done with a rad flush compound before replacing the coolant with new? Sometimes this is good, and other times it can free up scale and deposits and jam them in the radiator, causing a new rad to act like it has failed. Unlikely, but possible.

 

Maybe the most obvious one is that these engines are pretty picky about thermostats. It is generally accepted that they are on the list of items that you really NEED to get from OEM Subaru. Other brands do not seem to do well. Also, just to say it, the little burp valve (hole) in the thermostat has to install on the top side. Probably done that way, but just in case.... might be worth checking?

[Turbomister2]

I had this happen in a supra I bought. The temps would stay good as long as you drove it local but the moment you got on the highway the temps would creep and then If I pulled over it would drop and be fine for a little bit. Long story short the previous owner put the thermostat in and the  “air jiggler” was in the wrong position creating air pockets in the system.

Edited April 8 by Turbomister2

[Scubaboo]

In the 2 cars that I had similar symptoms, both times it was the radiator.